Companies like Uber and Lyft offer a great opportunity to make some quick cash. You'll need a clean driving record, a fairly new car and the authorization to work wherever it is that you live. If you have all of those things, you can work when it's feasible for you, whether that's in the middle of the day during rush hour, or in the wee hours of the night on a weekend. The choice is yours.
There are loads of resources for making money online as an affiliate. You could source products from ClickBank, Commission Junction, Rakuten Marketing, Share-a-Sale, Impact Radius and many others. Plus, many of the larger companies have their own affiliate programs as well. Do your due diligence and find the right company with a relevant product or service to your audience that you can sell as an affiliate.

Okay, so it's a Les Miz--style desperate measure. But if you've got the tresses and the desire to chop 'em off, why not make a little cash while you're at it? You post photos and a description on The Buy and Sell Hair (buyandsellhair.com), either with a listing price or an invitation to field potential buyers' offers. Recent sales include 14 inches of black hair that went for $500 and 16 inches of never-dyed strawberry blond hair that went for $800. Fantine never had it that good.

Open an Etsy store. If you have a creative talent or skill – whether it’s creating art, sewing clothes, or making keepsakes – you can open an online store on Etsy.com and sell your wares for some quick cash. With your own Etsy store, you’re left in charge of pricing and, ultimately, how much you make. See our detailed primer, “How to Make Money on Etsy.”

Having your own site to sell gently used handbags is probably going to be a really, really difficult endeavor for what its worth. It will be hard to get enough eyeballs/visitors on those bags to generate enough sales to make you any meaningful income (it’s an incredibly small niche and almost too specific in nature). Not to deter you from the idea completely but you’ll need to commit to several years of patience to really hit a home run in that field.

Websites like Care.com connect parents with babysitters. The company does all the background checking and other due diligence to put parents' minds at ease. Of course, you can appeal directly to people in your personal network, but if you're looking to generate recurring revenue sign up with a site marketing to parents looking for child care services.
Landscape. Look for brush-clearing, mowing, or woodcutting jobs, some of which may land you regular customers. This can save you money at the same time: if you are hired to pick up pine needles, use them to mulch your roses, which will appreciate their acidity and smothering effect on weeds; if you are hired to cut and clear a fallen tree, use it to heat your house that winter.
Join a startup accelerator: Another great option is to apply to a startup accelerator like Y Combinator, 500 startups, or TechStars, where a group of investors will help coach you, connect you with potential partners, and provide startup cash in return for a small stake in your company. The competition is tough to get into these, so don’t rely on them as your only path forward.

You have to be committed for this one because the application and training take quite a while. To teach for Kaplan Test Prep (212-492-5800, kaptest.com), you need to have scored in the 90th percentile on the test you want to teach. After you attend the required 20 hours of training, you'll start at about $20 bucks an hour. At the Princeton Review (877-312-7022, princetonreview.com), you'll earn $25 per hour, but you have to take a 30-minute test and give a five-minute lesson audition. If you pass, you begin a 30-to-60-hour training program. Finally, if you scored in the 99th percentile when you took the GMAT and aren't one of the five people still making millions in the business world, you can pull in $100 an hour teaching for Manhattan GMAT (212-721-7400, manhattangmat.com). Yes, there are some catches: You'll have to endure a phone interview, an online audition, a live audition and two months of (paid) training. You'll also have to explain to a classroom of naive corporate hopefuls why their career choice is doomed. Doomed!

You've got two choices: You can look for a gig with any number of organized companies, or go it alone, just you and the dogs. Petaholics (646-723-1282, petaholics.com) is hiring poochophiles who are available between 11am and 3pm, and who have experience with animals (walking them, working at a shelter or vet and owning/caring for a pet of your own all count). Expect to bank $50 to $200 a week. NYC Dog Walkers (917-912-3968, nycdogwalkers.com) is also hiring—it prefers employees who've owned a dog. Those who go the indie route and post flyers in their neighborhood charge $15 to $30 an hour.
If you have an eye for design and some experience of creating websites, then you could offer your services as a freelance web designer. You will need to create your own stylish website and have a few other projects that you can show potential clients to demonstrate your skills. You will also need to initially spend time emailing businesses to promote your services and find work.
Start a small business. Being passionate usually translates to a superior product and better service, which is especially sought after in the age of the anonymous, 1-minute online review. Worried that there isn’t a market for your interests? The fact is that though you may not personally know many people who want what you have to offer, thanks to the internet, there’s a huge market for niche-products (pigeon diapers, chainmail wedding dresses, you name it)… and you might just end up being a trend-setter. To create an online store, you can either make your own website or, if don’t want to self-host, you can sell on eBay or a similar site.

If you’ve ever wanted to try real estate investing but don’t want to deal with all the stress of being a landlord, you might want to consider investing with Fundrise. Fundrise is a new platform that allows you to invest directly in a real estate portfolio that a team of professionals identifies, acquires, and manages on your behalf. With a starting investment as small as $500, you get exposure to dozens of solid, value-producing assets.